Reception apparatus, antenna control method, and communication system

Abstract

A reception apparatus ( 10 ) includes plural antennas ( 101, 102 ) that are compatible with an LTE communication scheme and one reception processing section ( 100 ) processing a reception signal acquired by any one of the plural antennas ( 101, 102 ).

The invention claimed is: 
     
       1. A reception apparatus comprising:
 plural antennas configured to be compatible with a long-term evolution (LTE) communication scheme; 
 one reception processing section configured to process a reception signal acquired by any one of the plural antennas; 
 a signal quality measurement section configured to use, as a first trigger, detection of a synchronization signal used during an initial cell search, to calculate a signal quality value indicative of quality of the reception signal acquired by a corresponding one of the antennas used during the initial cell search; and 
 a control section configured to:
 perform switching of the antenna to another one of the antennas based on the signal quality value being less than a specific threshold, and 
 use, as a second trigger, lack of detection of the synchronization signal for a given period of time during the initial cell search, to perform switching between the antennas. 
 
 
     
     
       2. The reception apparatus according to  claim 1 , wherein the signal quality measurement section is further configured to calculate the signal quality value based on a result of calculation based on at least one of a received signal strength indicator (RSSI) value, a received signal quality indicator (RSQI) value, or a signal to interference plus noise ratio (SINR) value and at least one of a value associated with the RSSI value, a value associated with the RSQI value, or a value associated with the SINR value. 
     
     
       3. The reception apparatus according to  claim 1 , wherein
 the plural antennas include a first antenna and a second antenna, 
 the signal quality measurement section is further configured to calculate the signal quality value again after switching to the second antenna, and 
 based on the signal quality value calculated by the signal quality measurement section again after switching to the second antenna being less than the signal quality value measured by the signal quality measurement section before switching to the second antenna, the control section is further configured to perform switching to the first antenna. 
 
     
     
       4. The reception apparatus according to  claim 1 , wherein
 the plural antennas include a first antenna and a second antenna, 
 the signal quality measurement section is further configured to calculate the signal quality value again after switching to the second antenna, and 
 based on the signal quality value calculated by the signal quality measurement section again after switching to the second antenna is equal to or greater than the signal quality value measured by the signal quality measurement section before switching to the second antenna, the control section is further configured to set the second antenna as a reference antenna, and before performing the initial cell search, the control section is further configured to connect to the second antenna and wait. 
 
     
     
       5. The reception apparatus according to  claim 3 , wherein the first antenna and the second antenna are configured to acquire reception signals based on a low-speed communication scheme equivalent to a category-M1 (CAT-M1) scheme and a narrowband internet of things (NB-IoT) scheme. 
     
     
       6. An antenna control method, comprising:
 by a computer,
 using, as a first trigger, detection of a synchronization signal used during an initial cell search, to calculate a signal quality value indicative of quality of a reception signal acquired by an antenna used during the initial cell search; and 
 performing switching the antenna to another antenna in a case where the signal quality value is less than a predetermined threshold; and 
 using, as a second trigger, lack, for a given period of time, of detection of the synchronization signal used during the initial cell search, to perform switching between the antennas. 
 
 
     
     
       7. A communication system comprising:
 a base station; and 
 a reception apparatus, wherein the reception apparatus includes:
 plural antennas configured to be compatible with a Long-Term Evolution (LTE) communication scheme, 
 one reception processing section configured to process a reception signal acquired by any one of the plural antennas, 
 a signal quality measurement section configured to use, as a first trigger, detection of a synchronization signal used during an initial cell search, to calculate a signal quality value indicative of quality of the reception signal acquired by a corresponding one of the antennas used during the initial cell search, and 
 a control section configured to:
 perform switching the antenna to another one of the antennas in a case where the signal quality value is less than a predetermined threshold, and 
 use, as a second trigger, lack of detection of the synchronization signal for a given period of time during the initial cell search, to perform switching between the antennas.